Detector mechanism for nail head capping machines



May 23, 1933. w. c. DICKSON DETECTOR MECHANISM FOR NAIL HEAD CAPPING MACHINES Filed Jan. 4, 1929 3 Sheets-Sheet 1 ITnfenBv ml liam CBLcJisom m Y w A (J1me May 23, 1933.

w. c. DICKSON 1,910,681 DETECTOR MECHANISM FOR NAIL HEAD CAPPING- MACHINES Filed Jan. 4, 1929 3 Sheets-Sheet 2 1 4W UH L 1 14 I i x Q S:

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DETECTOR MECHANISM FOR NAIL HEAD CAPPING MACHINES Filed Jan. 4, 1929 s Sheets-Sheet s Z5 nix Lg i5: M 7 /5 J2 x .W. W

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Patented May 23, 1933 UNITED STATES \VILLIAM C. DICKSON, OF 'EVANSTON, ILLINOIS DETECTOR MECHANISM FOR NAIL HEAD CAIPING MACHINES Application filed January 4, 1929. Serial No. 330,279.

This invention relates to improvements in detector mechanism for nail head capping machines and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

The nail head capping machine with which the present invention is particularly concerned is of the type wherein nails are fedat one point individually to a plurality of dies and small masses of softer metal are fed at another point, individually to each of said dies upon the head of the nail therein, a reciprocating punch coacting with the dies at a third point to compress the mass of softer metal about the nail head to form the cap. In such a machine, separate mechanisms are employed to feed the nails and masses of softer metal and should either mechanism miss in its function, it is apparent that difficulties such as jammed diesor defective or uncapped nails, will occur when the particu lar die reaches that point at which the punch is to cooperate therewith.

The primary object of the present inven tion, is to provide means for changing the condition of an electric circuit associated with the capping machine, should a failure to feed a nail or a mass of softer metal occur, whereby this failure may be rectified and such adjustments made as Will eliminate jamming of the dies or the production of a defective capped nail.

Another object of the invention is to pro.- vide a detector mechanism, which include feelers which so coact with the dies as to immediately detect an abnormal condition ina die which has passed both feeding mechanisms so as to change the condition of said cir cuit in a manner notifying the operator of such an abnormal condition.

These objects of the invention as well as others, together with the many advantages thereof, will more fully appear as I proceed with my specification.

In the drawings Fig. 1 is a view in side elevation of a nail head capping machine, embodying the preferred form of detector.

Fi 2 is a horizontal sectional view through the machine as taken on the line 22 Fig. 1.

Fig.3 is a detail vertical sectional view on an enlarged scale as taken on the line 33 of Fig. 2.

Figs. 4- and 5 are detail vertical sectional views as taken on the line 44 and 55 respectively of Fig. 3. f

Referring now 'to theconstruction of the nail head capping machine to which my improved detector has been applied, 1 indicates as a whole the base of the machine and 2 and 3 indicate respectively the upright right and left hand side frame members respectively,

mounted on the base inthe manner found in 6 ordinary punch presses. Said side frame members each have a forward extension 4; near its bottom end upon which is mounted a bed plate 5 that is tilted downwardly and rearwardly as best shown in Fig. 1.

In the top ends of the side frame members'2 and 3 respectively is journalled a crank-shaft 6 and suitably mounted for reciprocation on guides carried by said side frame members is a cross head 7 actuated by a connecting rod 8 from the crank shaft. On that end of the crank shaft extending beyond the right hand frame member isa loose belt driven pulley 9 which may be connected to and disconnected from the crank by any suitable clutch mechanism, not shown. On that end of the crank shaft extending beyond the left hand frame member is a cam and disc carrying a crank pin 10 the purpose of which will appear later.

7 The bed plate 5 is substantially rectangular in plan and rotatively mounted, substantially centrally thereof is a circular die carrying plate 11. Fixed in the bed plate is a stub shaft 12 forming the axis about which the bed plate is rotative and disposed on said shaft above said plate are top and bottom discs 13 and 14 made of fibre. On the top end of said shaft is mounted. a pressure disc 15 and nuts 16 by which the friction of the discs 13 and 14: may

be adjusted so that the die carrying plate cannot rotate too freely and is held down snugly upon the bed plate.

In the periphery of the plate 11 is formed a plurality of arcuately spaced notches 17 and disposed a short distance inside said periphery is a plurality of die blocks 18, there being as herein shown, two of such blocks for each notch 17. Preferably said die blocks are inserted into openings in the plate 11 from below and said blocks and plate having engaging shoulders 19 (see Fig. 3) which correctly position the die blocks in the die car rying plate. When the die blocks are in said plate, they engage at their bottom ends 'upon the bed plate, which is provided with a groove 20 therein upon the die block circle, into which the bottom pointed ends of the nails 21 being capped, extend. The nails 21 employed herein are of the kind having a head 22 and an annular shoulder 23 just below said head.

In each die block is a central aperture in which is located a die 24, said aperture and die having engaging shoulders 25 which accurately position the die in the block, with the top end of the die disposed a suitable distance below the top of the die block. when a nail is arranged in the die and die block, the annular shoulder 23 engages upon the top of the die and spaces the nail head above the same as best shown in Fi g. 3.

In the left hand side of the bed plate is provided a forwardly andrearwardly extending undercut groove 26 in which reciprocates a bar 27. At the rear left hand corner of the bed'plate is an upright bracket 28 upon which is pivoted a bellcrank lever 29. One arm of sad lever is connected by a link 30 with the bar 27 and the other arm of said lever is pivoted to thebottom end of a connecting rod 31, the top end of which is operatively engaged with the crank pin 10. As is apparent, rotation of the crank shaft is translated in a reciprocating movement of said bar 27.

On the reciprocating bar, near its forward end, is mounted a spring pressed pawl 32 having one end adapted to enter one of the notches 17 in the die carrying plate 11 and as the bar moves rearwardly an amount or one step of rotative movement is imported to the carrying plate 11 equal to the angle between said notches. Holding pawls 33 and 34 respectively, each pivoted upon the bed plate, hold the plate against back lash or undesired. movement in the opposite direction and stop the plate so that the die blocks thereon are accurately positioned with respect to certain cooperating mechanisms as will later appear.

At the right hand side of the bed plate 11 is fixed a bracket 35 which overhangs a portion of the die carrying plate. Mounted on said bracket is a pair of nail feeding devices 3636 to each of which is connected a tube 37 down which nails are delivered to said feeding devices, one at a time, point down. from a nail hopper not shown. Said feeding devices are spaced apart a distance equal to the spacing between adjacent die blocks 18 so that for each step of movement of the die carrying plate, two nails are fed, each into adjacent die blocks. The number of feeding devices and die blocks served thereby may vary as desired, without affecting the spirit of the invention.

At the front of the bed plate is mounted a suitable mechanism indicated as a whole at 39 by which a small mass of softer metal may be fed into each die block, upon the top of the nail head exposed therein. Preferably each mass is in the form of a sphere 40 with lead as the desired metal because pellets of this kind in the form of buck shot of the proper size may be readily purchased in open market. A supply of such pellets is contained in a hopper 41 and to said hopper is connected a pair of delivery tubes 4242 in which the pellets stand in column form.

The bottommost pellet in each column is delivered into a die block upon the top of the heads of the nails fed thereinto by a forwardly and rearwardly reciprocating plate 43 mounted for guiding movement on a bracket plate 44 extending forwardly from the bed plate. This plate 43 is moved rearwardly into the position for delivering the pellets to the dies by a pair of springs 45 and is moved forwardly by a lever 46 pivoted to the bracket plate 44 as at 47. The long arm of said lever is connected by a link 48 to the front end of the bar 27 while the shorter arm of said lever engages the rear side of a roller 49 carried on the underside of the plate 43.

After the die blocks have passed the pellet feeding mechanism, each die block will be loaded, that is a nail 21 will be positioned in each die and a pellet 40 will be positioned in each die block above the head of the nail. therein. In the movement of the plate, as the loaded die blocks come into position beneath the cross head 7, a pair of punches 50 carried by the cross head, will in the descent thereof, enter the dies and compress the pellet into cap formation upon the nail head. As the cross head and punches ascend, the said die blocks move inte an other position in connection with means indicated generally as a whole as at 51 (see Figs. 1 and 2) by which the capped nails are removed from the dies and ejected from the machine. As this mechanism forms no particular part of the present invention it is only generally referred to as it is not believed necessary to go into details regarding the same.

Due to inaccuracies in the nails employed and also to the pellets employed, either of the associated mechan sms might miss in its function and fail to feed either a nail or a pellet into a die block. Should such a die block reach its position beneath the cross head. it is apparent that when the cross head descends and the punches enter the dies, difficulties arise. If no nail has been fed to the die block so that only a pellet is contained therein, the pellet is mashed into the i mechanism, no more nails can be fed thereto.

Such a jammed die block must be removed from the carrying plate-and cleared before itcan be returned for service. If no pellet has been fed to the die block which contains a nail, no amming occurs but the uncapped nail is ejected by the mechanism 51 along with the rest of the capped nails to mix therewith to the detriment of the manufacturer. To prevent the occurrence of such partly loaded die blocks from reaching thepunches and to notify the operator that such a partly loaded block has passed the pellet feeding mechanism, I provide a novel mechanism for changing the condition of an electric circuit. This circuit may be employed either to actuate suitable mechanism for stopping the machine or for sounding an audible alarm to attract the operators attention who may then manually stop the machine and rectify the fault causing the change in condition of said circuit. As shown herein for simplicity when the condition of said circuit is changed an alarm issounded.

On the bed plate 11 between the bracket 44 and groove 26 I mount a block of insulation 52 which carries a pair of laterally spaced, fixed contacts 53 and 54 respectively. Said contacts are both connected to the negative side of a source of current supply 55 such as a battery as ind cated diagrammatically in Fig. 4, by conductors 5656. An alarm' device 57 in the form of a bell. mounted at any convenient place on the machine, is connected onone side to the positive side of the battery by a conductor 58 and is grounded on its other side as at 59.

Mounted on the cross head 7 and extending forwardly therefrom is a bracket 60 from which depends an arm 61 having a horizontal foot portion 61*. Secured to the underside of said foot portion is a block 62, and on each side of the block is a bar 63, both pivoted upon a horizontally disposed cross pin 64 near the inner end of said block. On the outer end of said block on the under side thereof is a cross bar 6E2 which limits the downward swinging movement of the bars about the pin 64 but in no manner interferes with the upward swingmoy ement of said bars, which can float so to speak. Said bars are disposed parallel with a plane radial with respect to the axis of the die block carrying plate and are spaced apart a distance equal to that between adjacent die blocks as best shown in Fig. 2 and extend toward. and overhang the block of insulation 52. At the outer end of each arm 63 is provided a member in the form of an adjustable screw, which members register and are adapted for contactual engagement with the contacts 53 and 54 respectively, before mentioned.

Each bar also carries between its ends a feeler finger 66 in the form of an adjustable screw, which screws register with a pair of die blocks 18 as the same pass beneath said bars. In the downward movement of the cross head 7 and as the punches 50 enter a pair of die blocks to compress the pellets 40 about the heads 2:2 of the nails therein, the bars 63 will of course move downwardly therewith. In this downward movement'the feelers will engage upon the pellets 40 in the die blocks beneath the same and when both the nails and pellets are in said die blocks, thebars 63 are caused to swing upwardly about the pivot 64 so that the members 65 are held out of engagement with the associated contacts 53 and 54 respectively as best shown in dotted lines in Fig. 3.

However, in the absence of either the nail or-pellet from either die block, or should the nail be oneminus the shoulder 23 or should the pellet be undersize, then the support normally afforded the feelers 66 to swing the associated bar 63 upwardly is lacking with the result that one or the other of the members 65 will engage the associated contacts 53 and 54 and thus change the condition ofthe electric circuit before mentioned and sound the alarm 57. This notifies the operator that something is at fault and the machine is immediately stopped. An inspection will disclose the fault which is rectified and the machine is againstarted. Y

In making the members 65 and feelers 66 as before described, they may be so accurately adjusted that they will immediately detect any of the conditions above mentioned so that no uncapped or misshapened capped nails are delivered by the machine to mix with the good ones. Thus'uniformity in the'prodnet of the machine is assured. The detector mechanism is simple in construction, is eflicient in operation for its intended purpose and. cannot readily get out of order.

While in describing my invention I have referred in detail to the form and construction ofv the various parts as well as to the arrangement thereof, the same is to be considered merely as illustrative of one form of the invention, so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention 1. In combination with movable die members, into each of which a nail and a mass of cap material is fed for later assembly together therein, an electric circuit, including a contact, a reciprocating member, a feeler member pivoted to said reciprocating member for a limited swinging movement and operating in a part of the reciprocation of said member to have a definite relation with respect to said mass of cap material in a die aligned therewith, and a second contact carried by said feeler and operating to en.- gage the first mentioned contact upon a change in said definite relation between said feeler and mass of cap material to alter the condition of said circuit.

cating member, a bar pivoted with respect to said reciprocating member and limited in one direction of its swinging movement and a feeler carried by said bar and having a definite relation to said mass of cap material in a die when moved into alignment therewith during a part of the movement of said reciprocating member, said feeler operating to alter the condition of said circuit upon a change in said position relative to said mass of cap material.

3. In combination with movable die members into each of which a plurality of coacting elements are fed for later assembly together therein, an electric circuit, a support having a perpendicular reciprocating movement toward and away from each die member,'a feeler pivoted to said support, coacting parts on said support and "feeler respectively, for limiting the pivotal movement of said'feeler in a direction toward each die member when said support is moving away from-said diemember, said .teeler in the movement of said support toward each die member having a definite relation with respect to the position of one of said elements in said die member and operating to alter the condition of said circuit upon a. change in said definite position as when the tfeeler swings toward its limit of movement on said support.

4. In combination with movable die members into each of which a plurality of coacting elements are fed for later assembly together therein, an electric circuit including a contact, a support having a perpendicular reciprocating movement toward and away from each die member, a feeler pivoted to said support, coacting parts on said support and feeler respectively for limiting the pivotal movement of said feeler in a direction toward each die member when said support is moving away from said die member, a contact carried by said feeler and operable in the movement of said support toward each die to have a definite relation with respect to said first mentioned contact and cooperating therewith to alter the condition of said circuit upon a change in said definite position as when the feeler swings toward its l mit of movement on said support.

5. In combination with step by step rotatably movable die members into each of which a plurality of coacting elements are fed for t-er assembly together therein, an electric circuit, a support having a perpendicular reciprocating movement toward and away from each die member, a feeler pivoted to said support, coacting parts on said support and feeler respectively for limiting the pivotal movement of said feeler in a direction toward each die member when said support is moving away from said die member, said feeler in i the movement of said support toward each die member having a definite relation with respect to the position of one of said elements in a die member and operating to alter the condition of said circuit on a change in said definite position as when the feeler swings toward its limit of movement on said support.

6. In combination with step by step rotatably movable die members into each of which a plurality of coacting elements are fed for later assembly together therein, an electric circuit, and including a contact, a support having a perpendicular reciprocating movement toward and away from each die member, a feeler pivoted to said support, coacting parts on. said support and feeler respectively for limiting the pivotal movement of said feeler in a direction toward each die member when said support is moving away from said die member, a contact carried by said feeler and operable in the movement of said sup port toward each die member to have a definite relation with respect to said first mentioned contact andcooperating therewith to alter the condition of said circuit upon a change in said definite position as when the feeler swings towardsits limit of movement on said support.

7 In a detector mechanism of the kind described, a fixed contact, a support reciprocable toward and away from said fixed con tact, a bar pivoted at one end to said support, means on said support engageable by said bar for limiting the movement of said bar in a direction toward each die member when said support is moving away from said die member, a feeler and a contact carried by said bar and extending in the direction of the reciprocation of said support, and means adapted tobe engaged by the feeler in the movement of said support toward said fixed contact for swinging said bar in the other direction so as to hold the contact carried thereby out of engagement with said fixed contact, said feeler in the absence of said last mentioned means being inoperative to swing said bar in said other direction so that the contact carried by said bar engages said fixed contact.

8. In a detector mechanism of the kind described, a fixed contact, a support reciprocable toward and away from said fixed contact, a bar pivoted at one end to said support, means on said support engageable by said bar for limiting the-movement of said bar in a direction toward each die member when said support is moving away from said die member, a contact carried by the other end of said bar and extending in the direction of the reciprocation of said support, a feeler carried by said bar at a point between (he ends thereof, and means adapted to be engaged by the feeler in the movement of said support toward said fixed contact for swinging said bar in the other direction so as to hold the contact carried thereby out of engagement With said fixed contact, said feeler in the absence of said last mentioned means being inoperative to swing said bar in said other direction so that the contact carried by said bars engages said fixed contact.

In testimony whereof, I have hereunto set my hand, this 26th day of December 1928.

WILLIAM G. DIGKSON. 

